<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .box{
            width: 300px;
            margin: 100px auto 0;
        }
    </style>
</head>
<body>
<div class="box">
<div class="select">
    <input id="but" type="button" value="+">
    <input type="checkbox" name=''>
    <label>IP</label>
    <input type="text" placeholder="IP地址">
</div>
</div>
<script src="../../../js/jquery-3.3.1.js"></script>
<script>
    $(function(){

        $("#but").click(function () {
            var $item = $("#but").parent().clone();
            $item.children(":button").attr("value","-");
            $item.appendTo($(".box"))
        });
        $(document).on("click",".box input[value='-']",function(){
            $(this).parent().remove()
        })
    })
</script>
</body>
</html>